The invention relates to a directional or flow control valve.
The invention can generally be used in valves for adjusting a flow of pressure fluid, particularly in 2-way valves or continuously adjustable orifices. An important application field includes flow control valves that can keep a set flow rate constant independent of pressure fluctuations. This is achieved by virtue of the fact that an adjustable metering orifice is associated with a pressure compensator, which is acted on in the opening direction by both the force of a spring and a pressure downstream of the metering orifice and is acted on in the closing direction by the pressure upstream of the metering orifice. In principle, the pressure compensator can be situated before or after the adjustable metering orifice.
A flow control valve with a pressure compensator situated after a metering orifice is disclosed in the patent application DE 10 2004 019 748 A1 of the applicant. In this flow control valve, the metering orifice has a metering orifice slide that is guided in a valve bushing and spring-loaded in the closing direction. The opening cross section of the metering orifice is comprised of circumference openings of a star-shaped arrangement of bores in the metering orifice slide in cooperation with a circumferential control edge of an annular conduit in the valve bushing, which annular conduit is fluid-connected to an outlet connection B of the valve bushing. The outlet cross section of the fluid connection between the annular conduit and the outlet connection B can be changed by means of a pressure compensator spool that is contained in the valve bushing and that encompasses the metering orifice slide with an end section.
In this design, it is disadvantageous that in the region ot the star-shaped arrangement of bores, instances of relatively high flow resistance occur so that this directional or flow control valve has a correspondingly reduced performance.